Truck and trailer bodies and large shipping containers typically utilize pivoted double doors at one end wall to facilitate loading and unloading of the container compartment. Various door control mechanisms are used with such doors to retain the doors in a closed position and/or to reduce or eliminate racking. In the past, these mechanisms have included one or more shafts or lock rods which extend the height of the door and have latch members at each end which are engageable with keeper members on the door frame. They also have included a handle for rotating the lock rods, and handle-retaining elements attached to an associated door typically adapted to receive a padlock shackle or cable seal to lock the door in the closed position.
One mechanism of that type is illustrated in U.S. Pat. No. 3,737,183. The latch members include portions extending laterally from opposite sides of the lock rod and provided with cam surfaces engageable with surfaces of the keeper member.
One problem has arisen when these types of mechanisms are used on truck containers of the type carried piggy-back style on flat railroad cars. As the trains slow their speeds to travel through towns, thieves are able to steal the contents of the truck containers by climbing onto the cars and breaking or cutting the lock on the handle retaining elements. Since it is not uncommon that only the right hand door is locked, thieves are also able to break into truck containers by forcing the left hand door past the weather stripping which typically overlaps the left hand door.